I'm not sure if I have a problem or not. My temperature gauge doesn't work so I don't know if my truck is running hot or not. I bought a new thermostat sensor (from front of truck looking at engine - sensor just to the left of the thermostat housing), but the wire that plugs into it is broken. I'm going to go to the Pull-a-Part and get one off another truck and wirenut it on and see if the gauge will work then.

I replaced the water pump, radiator & cap, thermostat and hoses after I flushed the engine out. New 50/50 mix coolant, burped it. Top radiator hose gets hot, but the radiator cap does not. Take the cap off and the coolant is just sitting there. This is after it's been idling for about 25-30 minutes and driving it a quarter mile. Maybe that's the way it works today I don't know. I remember years ago the coolant would be circulating through the radiator at a pretty good clip.

This is a 1996 Dodge Ram 1500 2x4 5.2L 318 with about 216K miles on it.

Should I be concerned or am I just paranoid?

 

Just run the thing for a while with the cap off so you can see the coolant flowing when the thermostat opens. It'll cycle open/closed if things are working properly. If not... you'd know it already by the coolant mist on the windshield. But give the cap off check a try to set your mind at ease -- or raise an alarm, as the case may be.

 

When I was idling it before I had the cap off and the coolant wasn't moving. It idled for about 25-30 minutes with cap off and then I put the cap on and drove it a quarter mile or so and took the cap off and coolant still wasn't moving.

I bought a temperature gauge at Auto-Zone but the sensor mounting nut was way bigger than the temperature sensor hole on the engine. Plus, I wasn't sure if the stock temperature gauge sensor interacted with other parts or the truck computer...not that it would matter since it isn't working anyway. I'm going to the junk yard and get the plug that snaps into the temperature gauge sensor to see if that'll get the gauge to working.

When I replaced the water pump, thermostat and radiator I replaced the heater hoses and the top radiator hose but not the bottom one, so I'll replace it and see if that helps. I just wasn't sure about driving it not knowing for sure if the coolant is circulating or not and how hot the truck is running.

 

Your truck has two coolant temp sensors, the one over by the heater hose is for the gauge, the one by the thermostat housing (difficult to see) is for the PCM. (one wire sensor for the gauge, two wire sensor for the PCM.) You should be able to just kinda stuff the wire down onto the contact for the sensor, and get a reading on the gauge.

 

The plastic push plug is completely broken. All that's left is the little metal pin that is soldered onto the wire. In the sensor on the engine there is a metal pin that looks to be the male counterpart to he female connected to the wire. I may just try and solder these two together and fill in around them with a high heat silicon to keep moisture out. That'll take care of the gauge hopefully. I don't know if there is an after market (dash mount) gauge with a sensor that would fit in that little hole or not. I'll snoop the web to see.

I'm a little concerned about it not circulating coolant. I'll flush it out again, put in another thermostat and replace the upper and lower radiator hoses tomorrow. The water pump is new also, but if that were bad I think it would be making some type of noise or be wobbly.

We'll see.

 

With the cap off open the butterfly's on the throttle body manually. U can reach it easy from the passenger side of the vehicle. If the fluid goes down when you open the throttle ,it's circulating. And check your heat. If you have good heat it's circulating through the heater core. I'm kinda curious the fact u can open the radiator cap after its hot . It should be pressurized. My truck is the same there's a small leak where the heater core hose attaches. So it doesn't hold pressure. But it never gets hot . I have a 180 stat and even towing max load. It maby goes up to 195max. I just didn't have time to fix it yet. If your system is not pressureizing there is a leak somewhere. Micro boiling is a concern. Since ur temp gauge isn't working.